How Hardware Behaves in Sleep and Hibernate Mode

We all know that PCs have the possibility to enter a state of suspension , or that we can even put them to hibernate . We generally activate these modes to leave the PC “asleep” when we do not use it (or they are automatically activated in certain situations if we do not configure the PC to the contrary), but so that when we need it, it reactivates more quickly than turning it on from scratch. But do you know what happens to the PC hardware when the computer enters these power saving modes?

Both hibernating and putting the computer into a suspended state have the same purpose: to save energy when we are not using the PC, but at the same time allow us to resume what we were doing, and right where we were, in a very fast way. They are, of course, a quite comfortable way, at least more than turning on the computer and opening the programs or documents that we were working on.

How Hardware Behaves in Sleep and Hibernate Mode

However, both things are not the same, and essentially affects the hardware of the computer. Let’s see it.

What happens to hardware in sleep mode?

Sleep mode, also known as ” Sleep ” in English, actually has three possible power states (S1, S2, and S3) that depend entirely on what the system’s hardware and firmware allow, but the system can only enter one of these modes (that is, you cannot have components that enter S1 mode and others that enter S2 at the same time). On the other hand, S3 mode consumes less energy than S2, and this in turn less than S1.

Modo de suspensión

As the name suggests, the hardware is then left in a sleep or “sleep” state. In these states – any of the three possible – the processor enters a state of rest and only admits the command to wake up again, the same as the storage units (be they mechanical hard drives or SSDs). Of course, to preserve the state in which the system was, the RAM memory continues to operate at full capacity, and although the consumption is obviously much lower than having the computer fully turned on, it has some consumption.

This is the main difference, as we will see below, between hibernating or suspending the computer, since in sleep mode the RAM memory remains active, something necessary so that when we “wake up” the system, we find it all as we had it , including documents and open programs. In addition, this sleep mode is the fastest of all (when we wake up, we mean).

What happens to hardware when hibernating?

Hibernate mode corresponds to the S4 power state and therefore has lower power consumption than sleep mode. The processor and storage devices enter the same state as in the sleep mode, but the biggest difference is that here the RAM memory is also turned off , although previously all its contents have been dumped to a temporary file located in the system drive, called hiberfil.sys .

Since in this mode it is necessary to copy the contents of the RAM to the storage unit before entering hibernation mode, and when we “wake up” it is necessary to copy the contents of the file back to the RAM memory, it is substantially slower than sleep mode , and while it has the advantage of consuming less power, it has another added disadvantage because if your storage unit is an SSD, you will not only be consuming enough space but you will also be wearing down with those additional writes.

Suspend or hibernate the system, which is better?

Actually, the ideal is that if you are not going to use the PC for a while, turn it off. This way you not only minimize energy consumption, but you will also be avoiding the deterioration of the components. However, if you like being able to resume things where you had left them every time you turn on your PC, the best mode is really the sleep mode (versus hibernating), since in this mode you are not only avoiding wear and tear on the storage, it is also much faster.

As for power consumption, there is no worrying difference either, because RAM doesn’t consume too much. Of course, keep in mind one thing about sleep mode: since the data is in RAM, if the power went out or you manually turned off the computer, you could have errors after losing the RAM data and not being able to restart the system as it was, contrary to hibernation mode in which that would not matter when the data is in a non-volatile storage medium.

Destruir PC enfado

In any case, suspending or hibernating the system will depend on your needs. If in your case you have a laptop that does not have a long battery life, then it will be better to hibernate for you because the consumption is lower, but if you have an SSD or you have little storage space then you may prefer to suspend the equipment instead. In any case, we repeat, it is best to turn it off completely every time.